package core.app.zxing;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;

import com.google.zxing.ResultPoint;
import com.google.zxing.ResultPointCallback;

import java.util.ArrayList;
import java.util.List;

import core.android.camera.CameraManager;

/**
 * This view is overlaid on top of the camera preview. It adds the viewfinder rectangle and partial
 * transparency outside it, as well as the laser scanner animation and result points.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class ViewfinderView extends View implements ResultPointCallback {

    //四个绿色的角
    private String cornerColor = "#FF2A7C3B";//绿色
    private int cornerSize = 16;
    private int cornerLength = 60;
    private int cornerOffset = 8;

    private static final int[] SCANNER_ALPHA = {0, 64, 128, 192, 255, 192, 128, 64};
    private static final long ANIMATION_DELAY = 80L;
    private static final int CURRENT_POINT_OPACITY = 0xA0;
    private static final int MAX_RESULT_POINTS = 20;
    private static final int POINT_SIZE = 6;

    private final Paint paint;
    private Bitmap resultBitmap;
    private final int maskColor;
    private final int resultColor;
    private final int laserColor;
    private final int resultPointColor;
    private int scannerAlpha;
    private List<ResultPoint> possibleResultPoints;
    private List<ResultPoint> lastPossibleResultPoints;

    // This constructor is used when the class is built from an XML resource.
    public ViewfinderView(Context context, AttributeSet attrs) {
        super(context, attrs);
        // Initialize these once for performance rather than calling them every time in onDraw().
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        maskColor = Color.parseColor("#60000000");
        resultColor = Color.parseColor("#b0000000");
        laserColor = Color.parseColor("#ffcc0000");
        resultPointColor = Color.parseColor("#c0ffff00");
        scannerAlpha = 0;
        possibleResultPoints = new ArrayList<>(5);
        lastPossibleResultPoints = null;
    }

    @SuppressLint("DrawAllocation")
    @Override
    public void onDraw(Canvas canvas) {

        Rect frame = CameraManager.INSTANCE.getFramingRect();
        Rect previewFrame = CameraManager.INSTANCE.getFramingRectInPreview();
        if (frame == null || previewFrame == null) {
            return;
        }
        int width = canvas.getWidth();
        int height = canvas.getHeight();

        // Draw the exterior (i.e. outside the framing rect) darkened
        paint.setColor(resultBitmap != null ? resultColor : maskColor);
        canvas.drawRect(0, 0, width, frame.top, paint);
        canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
        canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, paint);
        canvas.drawRect(0, frame.bottom + 1, width, height, paint);


        /** Draw the corners*/
        Rect rect = frame;
        paint.setColor(Color.parseColor(cornerColor));

        /** top the corners*/
        canvas.drawRect(rect.left - cornerSize + cornerOffset, rect.top - cornerSize + cornerOffset, rect.left + cornerLength - cornerSize + cornerOffset, rect.top + cornerOffset, paint);
        canvas.drawRect(rect.left - cornerSize + cornerOffset, rect.top - cornerSize + cornerOffset, rect.left + cornerOffset, rect.top + cornerLength - cornerSize + cornerOffset, paint);
        canvas.drawRect(rect.right - cornerLength + cornerSize - cornerOffset, rect.top - cornerSize + cornerOffset, rect.right + cornerSize - cornerOffset, rect.top + cornerOffset, paint);
        canvas.drawRect(rect.right - cornerOffset, rect.top - cornerSize + cornerOffset, rect.right + cornerSize - cornerOffset, rect.top + cornerLength - cornerSize + cornerOffset, paint);

        /** bottom the corners*/
        canvas.drawRect(rect.left - cornerSize + cornerOffset, rect.bottom - cornerOffset, rect.left + cornerLength - cornerSize + cornerOffset, rect.bottom + cornerSize - cornerOffset, paint);
        canvas.drawRect(rect.left - cornerSize + cornerOffset, rect.bottom - cornerLength + cornerSize - cornerOffset, rect.left + cornerOffset, rect.bottom + cornerSize - cornerOffset, paint);
        canvas.drawRect(rect.right - cornerLength + cornerSize - cornerOffset, rect.bottom - cornerOffset, rect.right + cornerSize - cornerOffset, rect.bottom + cornerSize - cornerOffset, paint);
        canvas.drawRect(rect.right - cornerOffset, rect.bottom - cornerLength + cornerSize - cornerOffset, rect.right + cornerSize - cornerOffset, rect.bottom + cornerSize - cornerOffset, paint);


        if (resultBitmap != null) {
            // Draw the opaque result bitmap over the scanning rectangle
            paint.setAlpha(CURRENT_POINT_OPACITY);
            canvas.drawBitmap(resultBitmap, null, frame, paint);
        } else {
            // Draw a red "laser scanner" line through the middle to show decoding is active
            paint.setColor(laserColor);
            paint.setAlpha(SCANNER_ALPHA[scannerAlpha]);
            scannerAlpha = (scannerAlpha + 1) % SCANNER_ALPHA.length;
            int middle = frame.height() / 2 + frame.top;
            canvas.drawRect(frame.left + 2, middle - 1, frame.right - 1, middle + 2, paint);

            List<ResultPoint> currentPossible = possibleResultPoints;
            List<ResultPoint> currentLast = lastPossibleResultPoints;
            if (currentPossible.isEmpty()) {
                lastPossibleResultPoints = null;
            } else {
                possibleResultPoints = new ArrayList<>(5);
                lastPossibleResultPoints = currentPossible;
                paint.setAlpha(CURRENT_POINT_OPACITY);
                paint.setColor(resultPointColor);
                synchronized (currentPossible) {
                    for (ResultPoint point : currentPossible) {
                        canvas.drawCircle(
                                point.getX(),
                                point.getY(),
                                POINT_SIZE,
                                paint);
                    }
                }
            }

            if (currentLast != null) {
                paint.setAlpha(CURRENT_POINT_OPACITY / 2);
                paint.setColor(resultPointColor);
                synchronized (currentLast) {
                    float radius = POINT_SIZE / 2.0f;
                    for (ResultPoint point : currentLast) {
                        canvas.drawCircle(
                                point.getX(),
                                point.getY(),
                                radius,
                                paint);
                    }
                }
            }

            // Request another update at the animation interval, but only repaint the laser line,
            // not the entire viewfinder mask.
            postInvalidateDelayed(ANIMATION_DELAY,
                    frame.left - POINT_SIZE,
                    frame.top - POINT_SIZE,
                    frame.right + POINT_SIZE,
                    frame.bottom + POINT_SIZE);
        }
    }

    public void drawViewfinder() {
        Bitmap resultBitmap = this.resultBitmap;
        this.resultBitmap = null;
        if (resultBitmap != null) {
            resultBitmap.recycle();
        }
        invalidate();
    }

    /**
     * Draw a bitmap with the result points highlighted instead of the live scanning display.
     *
     * @param barcode An image of the decoded barcode.
     */
    public void drawResultBitmap(Bitmap barcode) {
        resultBitmap = barcode;
        invalidate();
    }

    public void addPossibleResultPoint(ResultPoint point) {
        List<ResultPoint> points = possibleResultPoints;
        synchronized (points) {
            points.add(point);
            int size = points.size();
            if (size > MAX_RESULT_POINTS) {
                // trim it
                points.subList(0, size - MAX_RESULT_POINTS / 2).clear();
            }
        }
    }

    @Override
    public void foundPossibleResultPoint(ResultPoint point) {
        addPossibleResultPoint(point);
    }

}
